Maximum age of Coregonus lavaretus in the Pechora River basin

The work analyzes data on the maximum recorded age of Coregonus lavaretus caught in different water bodies of the Pechora River basin (a total of 1948 specimens from 12 rivers, 18 different types of lakes and Korovinskaya Bay of the Pechora Sea). Field collections of materials were carried out in the period from 1985 to 2022. In different samples, the maximum age varied from 5+ to 21+. Residential groups are characterized by higher maximum age (5+ – 21+, median 9) compared to the semi-anadromous form of whitefish (5+ – 9+, median 8). The highest values (18+ and 21+) were recorded for whitefish living in hard-to-reach reservoirs of the lake-river system of the Maly Patok River (a second-order tributary of the Pechora River). The catchment area of this river is entirely part of the territory of the Federal National Park “Yugyd va”, included in the UNESCO World Heritage List. Today, this age is apparently the maximum for whitefish in water bodies of the European Northeast of Russia and is close to the limit values for this fish species. The theoretical age limit for whitefish varies from 12 to 44 years (on average about 25 years) and describes the linear growth of whitefish in different reservoirs of the Pechora River basin. It was estimated on the basis of the coefficients of the Bertalanffy equation (k and t0). A similar value (28–35 years) is obtained if the calculations use seven times the duration of maturation period (4+ – 5+ years). There are no significant differences in the maximum theoretical age between the semi-anadromous and residential forms of the whitefish. The maximum recorded ages of Pechora whitefish (17+ – 21+) can reach 70–80% of theoretical values. Apparently, the main factor limiting the lifespan of whitefish in natural reservoirs is intensive fishing.